How to Read a Maltose Syrup COA: DE, Brix and Sugar Profile Explained

A certificate of analysis is only worth the decisions it supports. For maltose syrup, the useful part is not the letterhead but the numbers: Brix, dextrose equivalent, the individual sugar fractions and a handful of quality limits. Read together, they tell you whether the batch will behave like the sample you approved, or quietly change your process. This guide explains what each figure means and how to spot an inconsistent COA.

First, check that the COA belongs to your batch

A COA without a batch or lot number, a production date and a clear product description is not traceable, and an untraceable document cannot settle a dispute. Confirm the batch code matches the container label and the shipping documents before you read a single value.

Brix: total dissolved solids

Brix is the concentration of dissolved solids, usually measured with a refractometer and reported as a percentage. It drives the syrup’s body, its dosing and, indirectly, its microbiological stability. A drop in Brix can mean the batch picked up moisture in transit, which dilutes the product and raises spoilage risk. Because the measurement is temperature-sensitive, the COA should state the temperature at which Brix was read or apply a correction.

DE: the average degree of hydrolysis

Dextrose equivalent expresses how far the starch has been broken down, on a dry basis, with pure dextrose defined as 100. A higher DE means more small sugars and greater fermentability; a lower DE means more larger saccharides and more residual body. DE is a helpful summary, but it is an average: it does not tell you the distribution of sugars, and two syrups with the same DE can perform differently.

The sugar profile is the detail that matters

The sugar profile reports the individual fractions, typically by HPLC. For maltose syrup the important ones are maltose, glucose (dextrose), maltotriose and the higher saccharides, often grouped as DP4 and above. This breakdown explains sweetness, crystallisation behaviour, hygroscopicity and fermentability better than any single number.

As-is versus dry basis

One of the most common sources of confusion is the basis on which results are reported. Because syrup is mostly solids but still contains water, a sugar figure expressed as-is is diluted by that water, while on a dry basis excludes it. If a COA mixes the two without saying so, comparisons against your specification can be misleading. Always check the basis, and convert consistently before judging a batch.

Contaminants, microbiology and other limits

Depending on the market, a COA may also report sulphated ash, sulphur dioxide, heavy metals, pH and microbiological results. These limits are usually set by food-safety regulation and by your own specification. Treat any missing or out-of-range result as a question to raise, not a detail to overlook: a supplier that routinely omits key parameters may be signalling a gap in quality control rather than a simple paperwork lapse.

How to reconcile a delivered batch

1. Match the COA batch code to the container and paperwork.
2. Check that every specification parameter is reported, with its basis and method.
3. Compare each value against your approved range, not just the pass or fail box.
4. Retain a sealed sample and re-test if the delivered product behaves unexpectedly.

A COA is a claim by the producer. Testing your own retained sample is the only way to confirm that the claim survives the journey.

Frequently Asked Questions